
Arch expansion is one of
the most common ways to eliminate crowding and correcting crossbites in growing
patients. I call it a game changer in the realm of
orthodontics. Expanders can easily solve
some orthodontic problems that were difficult to solve in orthodontic cases of
the past. Expanders have greatly reduced the need for routine extractions, and
have eliminated the need for many jaw surgical procedures.
To work successfully, palatal
expansion requires that the growth plate in the roof of the mouth (specifically,
the mid-palatal suture) has not yet fused. Typically, this fusion usually
occurs between 12 and 16 years of age, and usually occurs earlier in girls than
in boys.
An expander is attached
to the upper arch by bands placed around the upper first molar teeth. There are
many variations of expanders being used today in modern orthodontic offices, but at Wheeler Orthodontics we prefers the “HYRAX”—which is short for HYgenic RApid eXpander. Although there are removable expanders on the
market, glued in ones have a very important advantage in that they cannot be
lost, taken out, or forgotten. Hyrax-expanders are easily cleaned! Also
important is that glued in expanders like the HYRAX maintain an intimate contact
with the teeth, and the gentle force of the expansion does not overpower the
ability of a removable expander to maintain its position in the mouth, where removable ones can be easily dislodged.
While there may be some
initial discomfort right after an expander has been placed--just because there
has never been anything like that attached to the teeth before--for the most
part upper arch expansion is painless. Patients report that they feel a little “pressure”
on the teeth, in the roof of the mouth, behind the nose, and even between the
eyes as their expander is activated. This pressure fades within minutes. And
keep in mind that an expander does its job in about 3-4 months, then it is removed,
so it is not in the mouth for a long time.
Besides pressure, you
can also expect your child to speak a little funny for the first couple of days—which
will quickly pass. Additionally, you may
hear them slurping as their mouth creates extra saliva after expander
cementation. One of the most visible signs that the suture is opening (the
desired effect) is the appearance of a space between the upper central
incisors. The space is created as the expander pushes the two halves of the
palate in opposite directions. Once you have stopped activating the expander,
it is normal for the space to close quickly. This occurs by active closing
forces that the braces will provide, combined with the help of elastic fibers
in the surrounding gum tissues together working to return the teeth together
and to close the gap.

Because there is always a
potential relapse (movement back towards the original size) if expansion is
made to fast, Dr. Wheeler recommends that the expander is only turned once every
other day. This allows for a nice,
continuous, and harmonious rate of expansion that is biologically compatible
with the tissue of the growth plate and your child’s inherent rate of growth.
